46 BULLETIN 1003, U. S. DEPARTMENT OF AGRICULTURE. 



BATH PROCESS. 



An advantage of the bath process, another method which has been 

 used to a limited extent, is that the wood does not require previous 

 shredding. The wood is run into the retort on cars, and the retort 

 is flooded with a high-boiling material, such as molten rosin, pitch, 

 or tar, heated to a sufficiently high temperature. Most of the ex- 

 tracted turpentine and pine oils are volatilized at the temperature 

 of the bath, and the rest is blown out of the bath with steam. The 

 remaining wood, which is saturated with the rosin or other material 

 of the bath, may be destructively distilled to recover the light and 

 heavy crude oils, tar, charcoal, and pitch. 



FEASIBILITY OF DISTILLING WESTERN YELLOW PINE. 



Yellow-pine stumps of a quality such as to yield more than 12£ 

 gallons a cord, the average yield from medium-grade stumpwood, 

 of merchantable wood turpentine, of the properties shown in Table 

 18, and other products in corresponding proportion, are compara- 

 tively scarce. " Fat " or " pitchy " stumps, averaging 20 gallons of 

 merchantable turpentine a cord, are not sufficiently numerous to be 

 considered in a class by themselves as an impediment to land-clearing 

 operations, and would need to be hauled for long distances in supply- 

 ing wood to distilling plants. 



The daily yield from a 10-cord plant and the market value of the 

 products from the rich portion of medium-grade stumps, based on 

 the yields obtained in these experiments and on the prevailing eastern 

 prices June, 1918, using the ordinary ovens in general use, would be 

 approximately as follows : 



Merchantable turpentine 127 gallons © $0. 50 $63. 50 



Pine oil 13 do. @ .40 5.20 



Light oil (at tar oil prices) 35 do. @ .20 7.00 



Heavy oil (at tar prices) 275 do. (6 barrels) ® $0.15 41.25 



Pitch 7 barrels (1,400 pounds) @ $3.50_. 24.50 



Charcoal 350 bushels (7,110 pounds) @ $0.12_ 42.00 



183. 45 

 Total value of products a cord of selected medium-grade resinous 



wood or heartwood $18. 36 



The average yield and market value of the products recovered 

 from a cord of rich stumpwood on the same basis are estimated to be : 



Merchantable turpentine 19. 8 gallons @ $0. 50 $9. 90 



Pine oil 2.0 do. @ .40 .80 



Light oil 4.5 do. @ .20 .90 



Heavy oil 46.0 do. @ .15 6.90 



Pitch 138. pounds @ 3. 50 a barrel 2. 41 



Charcoal ' 38. bushels (790.0 pounds) @ $0.12. 4. 56 



S. Total value of products a cord 25. 47 



